Bench-dog support pins the tails on your workpiece
When cutting dovetails, I prefer to cut the pins first because I find them easier to transfer to the tail boards given the space between the pins. However, I struggle to hold the pin board steady while scribing the tails.
To add stability to that process, glue a dowel that fits your workbench's dog holes into the end of a flat, square board. Mount the support on your workbench, clamp the pin board to the support atop the tail board, and scribe away!
—Alejandro Balbis, Longueuil, Que.